Is infertility a common problem?

Yes. About 10 percent of women (6.1 million) in the United States ages 15-44 have difficulty getting pregnant or staying pregnant, according to the Centers for Disease Control and Prevention (CDC).

Is infertility just a woman's problem?

No, infertility is not always a woman's problem. Both women and men can have problems that cause infertility. About one-third of infertility cases are caused by women's problems. Another one third of fertility problems are due to the man. The other cases are caused by a mixture of male and female problems or by unknown problems.

What causes infertility in men?

Infertility in men is most often caused by:

A problem called varicocele (VAIR-ih-koh-seel). This happens when the veins on a man's testicle(s) are too large. This heats the testicles. The heat can affect the number or shape of the sperm.

Other factors that cause a man to make too few sperm or none at all.

Movement of the sperm. This may be caused by the shape of the sperm. Sometimes injuries or other damage to the reproductive system block the sperm.

Sometimes a man is born with the problems that affect his sperm. Other times problems start later in life due to illness or injury. For example, cystic fibrosis often causes infertility in men.

What increases a man's risk of infertility?

A man's sperm can be changed by his overall health and lifestyle. Some things that may reduce the health or number of sperm include: